1. Field of the Invention
The present invention generally relates to computers and software, and more particularly, to the apparatus and method for providing flexible communication of data modification of Web resources between multiple client browsers, where the Web resources are on a server.
2. Description of Related Art
As known in the art, the Internet is a world-wide collection of networks and gateways that use the TCP/IP suite of protocols to communicate with one another. At the heart of the Internet is a backbone of high speed data communication lines between major nodes or host computers consisting of thousands of commercial government educational and other computer systems that route data and messages.
World Wide Web (WWW) refers to the total set of interlinked hypertext documents residing on hypertext transfer protocol (HTTP) servers all around the world. Documents on the WWW, called pages or Web pages, are written in hypertext mark-up language (HTML) identified by uniform resource locators (URL) that specify the particular machine and pathname by which a file can be accessed and transmitted from node to node to the end user under HTTP. A Web site is a related group of these documents and associated files, scripts, subprocedures, and databases that are served up by an HTTP server on the WWW.
Users need a browser program and an Internet connection to access a Web site. Browser programs, also called "Web browsers," are client applications that enable a user to navigate the Internet and view HTML documents on the WWW, another network, or the user's computer. Web browsers also allow users to follow codes called "tags" imbedded in an HTML document, which associate particular words and images in the document with URLs so that a user can access another file that may be half way around the world, at the press of a key or the click of a mouse.
These files may contain text (in a variety of fonts and styles), graphic images, movie files, and sounds as well as java applets, perl applications, other scripted languages, active X-controls, or other small imbedded software programs that execute when the user activates them by, for example, clicking on a link. Scripts are applications that are executed by a HTTP server in response to a request by a client user. These scripts are invoked by the HTTP daemon to do a single job, and then they exit.
One type of script is a common gateway interface (CGI) script. Generally, a CGI script is invoked when a user clicks on an element in a Web page, such as a link or image. CGI scripts are used to provide interactivity in a Web page. CGI scripts can be written in many languages including C, C++, and Perl. A CGI-BIN is a library of CGI scripts applications that can be executed by a HTTP server.
A key difficulty with communication between client browsers is caused because the client browser will not create a network connection to any computer other than the one from which the client browser code itself was loaded. Therefore, if a client browser changes data in a Web resource that is being shared or accessible by other browsers, the ther browsers will not be made aware of the Web resource data change.
However, until now, applications running in browsers have lacked the ability to notify other browsers running the same application of changes to their underlying database.